Scarifier teeth are normally installed in an angular position, as in a socket having a hole disposed at an angle, such as 45.degree., to the radius of a drum on which the socket is mounted, while an annular recess near the rear end of the hole is adapted to receive a spring which expands into the recess. This spring is contained in an annular slot near the rear of a rear stem of the tooth, which also has a body and, at the front end of the body, a tip of hard metal, such as tungsten carbide or an alloy having similar wear resistant qualities. This tip is predominantly circular, so as to fit into a central hole in the body, but has a conical point. The tip is normally held in place on the body by weld metal deposited around the periphery of the rear edge of the conical point.
The socket in which the tooth is installed has an at least partially open rear end, so that a pin, chisel or the like may be inserted into the socket to drive the tooth out of the hole when the tip is broken or worn, or the tooth should be replaced for some other reason. Normally, heavy hammers have been used to drive the teeth out of the sockets. The hole in the socket also has a bevel at its entrance, so as to compress the spring contained in the slot in the stem of the tooth, so that the tooth may be moved into the hole until the spring reaches the recess of the socket hole. Again, heavy hammers have been used in driving the teeth into the sockets, which has resulted in an undue amount of breakage of teeth, particularly the tips formed of relatively hard metal. In addition, the use of heavy hammers to drive worn or broken teeth out and to install new teeth requires an undue amount of time. Since the drum on which the sockets are located in both a radial and axial spaced relationship may be on the order of 3 feet in diameter and 8 to 10 feet wide, and may have on the order of 110 sockets and teeth, to drive out the broken or worn teeth with a heavy hammer and replace them again, with the use of a heavy hammer, requires an undue amount of time. Additional time is required, for heavy hammer operations, to drive out teeth that have been broken by installation with such a hammer and reinstalling new teeth. Certain users have experienced a necessity for replacing teeth for ripping asphalt every four hours, and to replace teeth for ripping concrete sometimes six times a day. Since the ripping machines are normally rented at a cost, in certain instances, of $500.00 per hour, excessive down time of the machines, particularly due to the amount of time involved in heavy hammer operations, is quite costly.
Among the objects of this invention are to provide a tool for installing scarifier teeth which enables a percussion instrument, such as an air hammer, to be utilized; to provide such a tool which is not required to engage the hard metal tip of the teeth, but rather a portion of the body of the teeth; to provide such a tool which does not tend to wedge on the tooth during installation; to provide such a tool which may be mounted on the drive pin of an air hammer, such as identical to that which may be used for driving the teeth out of the socket; to provide such a tool which may be readily manufactured, but with a variation to accommodate different styles of teeth, such as used for ripping concrete and for ripping blacktop; and to provide such a tool which is effective and efficient in operation and tends to have a relatively long, useful life.
U.S. Pat. No. 3,769,683 discloses a sliding hammer device provided with a pivoted loop which may be placed over a cutter bit for a mining, excavating or earth working machine to remove the bit when worn. A head member of the tool may be provided with a depression or recess which fits over the cone-shaped nose of that style of bit, with the hammer impacted against an appropriate flange to drive the tooth into a socket. However, the included angle between opposite interior surfaces of the conical recess is approximately 30.degree., i.e. the bevel on the inside of the recess is approximately 15.degree. to the axis of the tool. Thus, such a tool is not adapted for use with scarifier teeth, since it tends to become wedged on the conical surfaces.